Potential of Thermal Analysis To Estimate Chemical Composition and in Vitro Fermentation Characteristics of Maize

Abstract

Organic matter and cell wall degradation (OMD and CWD) are important quality traits of maize which may be estimated by in vitro assays using rumen fluid. However, these assays have some large disadvantages which stimulate research for alternative methods. The objective of this study was to evaluate the potential of the thermal analysis techniques, differential scanning calorimetry (DSC) and thermogravimetry (TG), to estimate OMD, CWD, and related forage quality traits of maize. For all DSC and TG properties distinguishable in DSC and TG thermograms, large variations existed among 25 maize samples. Multiple linear regression models including both DSC and TG variates could explain a major part of the variation of most forage quality traits. The relatively short analysis time, the high reproducibilty of measurements, and the high predictive potential as shown by the low standard error of prediction indicate that DSC and TG may be used to predict forage quality characteristics of maize. Keywords: Degradability; cell wall; maize; differential scanning calorimetry; thermogravimetry; multiple linear regression

Thermogravimetric evaluation of perennial ryegrass (Lolium perenne) for the prediction of in vitro dry matter digestibility

“…The interpretation of thermal degradation steps of plant materials is complex as the combustion of low-and high-molecular-weight constituents of cell walls can overlap and this observation has been demonstrated for maize (Marvin et al, 1996), wood (Krigstin et al, 1993) and flax fibre (Sharma & Kernaghan, 1988). The active decomposition bands represented as PK1, PK2 and PK3 may be linked to the combustion of carbohydrates and phenolic acids (free), celluloses and lignin cross-linked to hemicelluloses, respectively.…”

“…The thermal degradation properties of cell wall constituents of maize stalks have been related to chemical composition (Marvin et al, 1996). The nutritional value of maize measured as cell wall digestibility has been evaluated by both thermogravimetry (TG) and differential scanning calorimetry (DSC) (Marvin et al, 1996). Mellon & Sharma (2002) reported a preliminary study on the use of TG for assessing digestibility of perennial ryegrass.…”

“…The carbohydrate and fibre fractions of forage grass can vary during successive cuts in a year as a result of seasonal factors, including day length and day and night temperatures, which can induce change from a vegetative to a reproductive growth stage, leading to a reduction in DMD (Van Soest, 1982;Gilliland et al, 1995). The thermal degradation properties of cell wall constituents of maize stalks have been related to chemical composition (Marvin et al, 1996). The nutritional value of maize measured as cell wall digestibility has been evaluated by both thermogravimetry (TG) and differential scanning calorimetry (DSC) (Marvin et al, 1996).…”

Thermal decomposition, chemical composition, in vitro digestibility and gas production and in situ degradability of oilseed residues from the biofuel industry

“…The in vivo evaluation of the nutritive value of feeds through the measurement of feed intake, total tract apparent digestibility and productive performance requires more time and cost as compared with laboratory level experiments. The simultaneous measurements of TG and DSC outperform wet chemistry measurements of samples to predict chemical components such as carbohydrates, ash and energy (Marvin et al 1996). Additionally, Marvin et al (1996) and Sharma et al (2008) reported that thermal analysis gave physical properties associated with quality of ruminant feed.…”

“…The use of fiber-rich products, such as agroindustrial by-products, can reduce the cost of feeding animals (Zambom et al 2001). Additionally, Marvin et al (1996) and Sharma et al (2008) reported that thermal analysis gave physical properties associated with quality of ruminant feed. The in vivo evaluation of the nutritive value of feeds through the measurement of feed intake, total tract apparent digestibility and productive performance requires more time and cost as compared with laboratory level experiments.…”